Production of the Hard X-ray Mirror of the ASTRO-H satellite

1. Production of the Hard X-ray Mirror of the ASTRO-H satellite Hironori Matsumoto (Nagoya University) & HXT team 1. The ASTRO-H satellite 3. Mirror Production ASTRO-H is an international X-ray observatory which will be launched in FY2015. More than 160 scientists from Japan, USA, Europe, and Canada participate this project, and the Japanese team takes the lead. Below is a summary of the mirror production of the HXT. ASTRO-H carries four X-ray instruments which realize X-ray observations of the universe in the very wide energy range from 0.3 to 600 keV. Thermal Forming (Preparing mirror foils) Al Sheet Al sheet (t0.2mm) roller 2. The Hard X-ray Telescope (HXT) ASTRO-H carries two Hard X-ray Telescopes (HXTs). Two Hard X-ray Imagers (HXIs) are placed at the foci of the HXTs, and this combination makes it possible to take pictures of the high-energy universe with high-energy X-rays from 5 to 80keV. Also it is possible to obtain X-ray spectra with good energy resolution. Stack on mandrel Mirror foil Heat forming (200℃, 12hrs) Image point Sputtering (multilayer deposition) The HXT mirrors employ tightly-nested, conically-approximated thin-foil Wolter-I optics (a schematic view is shown in the right figure). X-ray source We have three sputtering machine. Inside of the machine, a multilayer is deposited onto the surface of a glass mandrel. It takes 4 to 12 hours to complete one multilayer. http://www.x-ray-optics.com/ Glass Mandrel The HXT comprises foils 450 mm in diameter and 200 mm in length, with a focal length of 12 m. To obtain a large effective area, 213 aluminum foils 0.2 mm in thickness are tightly nested confocally. C Pt rotate before after Replica Epoxy is sprayed to the Al sheet. The glass mandrel deposited the multilayer is pressed against the Al sheet inside a vacuum chamber. Finally the Al sheet is peeled off from the mandrel. 12m Glass mandrel with multilayer Put Al sheet The HXT utilizes two principles for reflecting X-rays: the total reflection for low-energy X-rays (E<10keV) and the Bragg reflection for high-energy X-rays (E>10keV). The mirror surfaces are coated with Pt/C depth-graded multilayers for the Bragg reflection. epoxy Al sheet with epoxy 4. HXT properties A cross section of the HXT mirror surface (left). The layer thickness (d) gradually changes to reflect X-rays of various energies. In the case of HXT, the thickness ranges from 24 to 136Å. The right panel shows reflectivity curves for a single layer (black; d=100Å), a multilayer (red; d=40Å, N=30, Γ=0.4), and a depth-graded multilayer (blue; d=26-50Å, N=78, Γ=0.4), where N is the number of layers, and Γ is a fraction of Pt. One of the two HXTs (HXT-1) was completed in the last year. The characteristics of the HXT1 were measured using the synchrotron facility, SPring-8. The image of a point source at E=30keV is shown in the left panel. The encircled energy function is shown in the middle, and the half power diameter is 1.92 arcmin at E=30keV. The effective area is shown in the right, and it is larger than the required values. 30keV